[PATCH] D42969: [Sema] Fix decltype of static data members

[Mikhail Maltsev via Phabricator via cfe-commits]

miyuki created this revision.
miyuki added reviewers: faisalv, rsmith.
miyuki edited the summary of this revision.

According to the C++11 standard [dcl.type.simple]p4:

  The type denoted by decltype(e) is defined as follows:
  - if e is an unparenthesized id-expression or an unparenthesized
    class member access (5.2.5), decltype(e) is the type of the entity
    named by e.
    

Currently Clang handles the 'member access' case incorrectly for
static data members (decltype returns T& instead of T). This patch
fixes the issue.


https://reviews.llvm.org/D42969

Files:
  lib/Sema/SemaType.cpp
  test/CXX/dcl.dcl/dcl.spec/dcl.type/dcl.type.simple/p4-cxx0x.cpp


Index: test/CXX/dcl.dcl/dcl.spec/dcl.type/dcl.type.simple/p4-cxx0x.cpp
===================================================================
--- test/CXX/dcl.dcl/dcl.spec/dcl.type/dcl.type.simple/p4-cxx0x.cpp
+++ test/CXX/dcl.dcl/dcl.spec/dcl.type/dcl.type.simple/p4-cxx0x.cpp
@@ -12,13 +12,18 @@
 
 const int&& foo();
 int i;
-struct A { double x; };
+struct A {
+  double x;
+  static int y;
+};
 const A* a = new A();
 
 static_assert(is_same<decltype(foo()), const int&&>::value, "");
 static_assert(is_same<decltype(i), int>::value, "");
 static_assert(is_same<decltype(a->x), double>::value, "");
 static_assert(is_same<decltype((a->x)), const double&>::value, "");
+static_assert(is_same<decltype(a->y), int>::value, "");
+static_assert(is_same<decltype((a->y)), int&>::value, "");
 static_assert(is_same<decltype(static_cast<int&&>(i)), int&&>::value, "");
 
 int f0(int); // expected-note{{possible target}}
Index: lib/Sema/SemaType.cpp
===================================================================
--- lib/Sema/SemaType.cpp
+++ lib/Sema/SemaType.cpp
@@ -7859,8 +7859,9 @@
     if (const ValueDecl *VD = dyn_cast<ValueDecl>(DRE->getDecl()))
       return VD->getType();
   } else if (const MemberExpr *ME = dyn_cast<MemberExpr>(E)) {
-    if (const FieldDecl *FD = dyn_cast<FieldDecl>(ME->getMemberDecl()))
-      return FD->getType();
+    if (const ValueDecl *VD = ME->getMemberDecl())
+      if (isa<FieldDecl>(VD) || isa<VarDecl>(VD))
+        return VD->getType();
   } else if (const ObjCIvarRefExpr *IR = dyn_cast<ObjCIvarRefExpr>(E)) {
     return IR->getDecl()->getType();
   } else if (const ObjCPropertyRefExpr *PR = dyn_cast<ObjCPropertyRefExpr>(E)) {


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